U.S. Pat. No. 7,286,245 B2 describes a method for determining an influence of an optical system from the polarization state of optical radiation. This method involves determining a Jones matrix of the optical system in two measurement stages. In the first measurement stage, input-side radiation having defined polarization states is radiated successively onto the optical system. The intensities of the resulting output-side polarization states of the radiation emerging from the optical system are thereupon measured using a polarization analyzer. A phase-reduced Jones matrix is calculated therefrom. In a second measurement stage, a global phase term is determined through interferometric measurement. The phase-reduced Jones matrix determined in the first measurement stage is thereupon combined with the global phase term in order to obtain the complete Jones matrix of the optical system.
Polarization parameters, such as the retardation, for instance, can be determined from the Jones matrix. However, if the environmental conditions change during the measuring method described above, then the measurement result can be corrupted thereby.